Asymptomatic Unexplained Visual Field Loss Diagnosed as Early Retinitis Pigmentosa without Pigmentation: A Case Report

PURPOSE: We report a case of asymptomatic unexplained visual field loss diagnosed as early retinitis pigmentosa (RP) without pigmentation. CASE SUMMARY: A 33-year-old woman was referred to us with a constricted visual field (C24-2) before laser-assisted in-situ keratomileusis surgery. The visual field test (C30-2) revealed significantly decreased sensitivity between 15 to 25 degrees in both eyes. Close fundus examination revealed a subtle greyish retinal atrophic lesion along the vascular arcade and fluorescein angiography revealed a window defect in accordance with a retinal atrophic lesion in both eyes. Optical coherence tomography showed decreased retinal thickness around the macula. Electroretinogram revealed decreased b waves in rod response. Based on these findings, we diagnosed the patient with early RP without pigmentation. CONCLUSIONS: The possibility of early RP without pigmentation presenting as slight atrophy around the macula without significant pigmental degeneration should also be considered if a patient presents with peripheral visual field constriction without other symptoms. The ophthalmologist should ensure that the location of the visual field defect matches the location of the lesion. In addition, a detailed fundus examination with macular optical coherence tomography can be helpful to diagnose such a lesion.

Bupivacaine Injection to Lateral Rectus in Abducens Nerve Palsy

A 49-year-old female presented with bilateral abducens nerve palsies. She had 75 prism diopter esotropia. The extraocular movement of the lateral rectus was -1 limitation for the right eye and -4 limitations for the left. After performing orbital magnetic resonance imaging (MRI), 2 mL of bupivacain (5 mg/mL) was injected into the left lateral rectus (LR). One month after injection, a further orbital MRI was performed. Subsequently, recession of both medial rectus (6 mm) and resection of the left LR (9 mm) were performed. After one month, bupivacaine had no hypertrophic effects. There was little change in angle of deviation. The orbital MRI scan showed a 1.91% increase in volume compared to the muscle prior to the injection. Histological findings showed no muscle fibers of the left LR muscle, only the fiber nucleus and the collagen that replaced the fibers. We report on the changes in stiffness and muscle volume and on the histology of the muscle one month after injecting bupivacaine into the paralyzed left LR muscle combined with standard surgical treatment.